Attachment jibs for crane booms including telescoping booms are known in the art and exist in a number of forms. Generally, such booms are employed to increase the normal maximum length of the boom so that higher elevations may be reached. The known jibs are quite limited in their utility and an example of their limited use is to place a relatively light load on the roof of a building whose height is within the reach of the jib when the crane boom on which the jib is mounted is extended.
With the above in mind, it is the object of this invention to provide a far more versatile attachment jib for cranes which includes a more stable, secure and convenient mounting base which is removably attachable to existing shaft elements found on the nose block of most telescoping boom construction cranes.
Another object is to provide an attachment jib having its own boom which is extensible and retractable and which may be luffed through a wide angle to enable a more efficient utilization of different working devices which can be supported by the jib.
Another object is to provide an attachment jib of the above-mentioned type whose extending and luffing hydraulic cylinders may be conveniently operated by the hydraulic system of the crane.
Still another object is to provide an attachment jib having an optional worker support which remains level under the influence of gravity and which, when used, places the worker close to the controls for the jib and working implements carried by the jib.
Other features and objects of the invention will become apparent during the course of the following detailed description.